The cleanup and handling of cattle, swine and poultry manure has become a critical issue in the management and disposal of animal waste. Animals have been raised for centuries for food and previously such animals grazed in fields or pens. Current methods of raising livestock include housing in high concentrations within a confined space. Numerous drawbacks of such confinement include high concentrations of waste that must be removed from the confined space. The manure produced must be removed regularly to ensure adequate sanitation and to prevent disease.
When solid waste is used as fertilizer in fields, increased levels of phosphorus, nitrogen, and potassium are found in the soils. When liquid waste is used as fertilizer in fields, increased levels of nitrogen rich ammonium and ammonia are found in the soils. Either scenario may result in the leaching of such chemicals into drainage waters and run-off streams.
There has been increasing publicity and stricter environmental requirements and enforcement because of the continuing concern over maintaining water quality in watershed areas due to the release of manure as normal operational discharges from dairy cattle, beef cattle, swine, poultry and other concentrated animal feeding operations. Current technologies for separating solids and nutrient components of such animal waste have limitations, are costly to operate, and result in the use of large quantities of fuel and labor in order to provide solid and water-based effluents that can either be recycled or are environmentally acceptable to spread on farmlands.
Accordingly, there is currently a need for an improved process and separation system for treating animal waste that is low in capital equipment cost, low in waste transportation cost, prevents pollution of water resources, simple to operate, and that provides solid and liquid effluents containing beneficial and useful nutrients critical for food production.